Online Color Research Articles

An On-Line Spectrophotometer for Color Measurement of Moving Samples

The development of a reflectance spectrophotometer designed specifically for on-line non-contact measurement of color is discussed. The on-line spectrophotometer utilizes two concepts new to the field of color measurement:1.A pulsed-xenon flashtube light source2.A diffraction grating spectrometer and detector array for parallel wavelength sensing.Both of these concepts result in an instrument with improved performance capabilities compared with the tristimulus colorimeters previously used for on-line color measurement. These capabilities include improved accuracy, non-contact measurement of moving samples, long term stability, and agreement of measurements made with multiple instruments. The on-line spectrophotometer is presently used as a key element in the measurement and control of color in the textile, plastics and paper industries. Several applications will be described.

The development of dynamic color control on a paper machine

This paper discusses the theoretical and practical aspects of on-line color control that is used successfully on a paper machine at Consolidated Papers, Inc. The control design schemes for digital controllers are given. Simulation and actual process results are also reported.